JPH0659452A - Polymerizable unsaturated polyurethane and ultraviolet-curing resin composition using the same - Google Patents

Abstract

PURPOSE:To obtain a UV-curing resin compsn. for coating an optical fiber excellent in reliability over a long period of time, having low viscosity and ensuring satisfactory work efficiency by allowing specified polyether polyol to react with polyisocyanate and a hydroxy compd. CONSTITUTION:Polyether polyol obtd. by block-copolymerizing polybutylene glycol as a stock polymer with alkylene oxide is allowed to react with polyisocyanate and a compd. having a polymerizable unsatd. group and active hydrogen reacting with an isocyanato group to obtain the objective polymerizable unsatd. polyurethane. The objective UV-curing resin compsn. contains this polymerizable unsatd. polyurethane, a monomer having an ethylenic unsatd. bond and a photopolymn. initiator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymerizable unsaturated polyurethane and an ultraviolet curable resin composition containing the same, and more particularly to an ultraviolet curable resin composition for coating an optical fiber.

[0002]

2. Description of the Prior Art Optical fibers are very fragile and easily damaged.
Moreover, it is well known that optical transmission loss increases due to contamination. Therefore, conventionally, immediately after spinning an optical fiber, the glass surface is primarily coated with a material having a low elastic modulus, and then secondary coated with a material having a high elastic modulus.

In recent years, ultraviolet curable resins have been used as these materials in terms of productivity. Further, an ultraviolet curable resin is also used when bundling optical fibers having a primary coating and a secondary coating into a tape.

Polyether urethane acrylate is widely used as a polymerizable unsaturated polyurethane used in the ultraviolet curable resin. Examples of the polyether polyol component constituting the known polyether urethane acrylate include, for example, polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, random copolymers of propylene oxide and ethylene oxide, and random tetrahydrofuran and propylene oxide. Examples thereof include a copolymer, a random copolymer of tetrahydrofuran and ethylene oxide, an ethylene oxide adduct of bisphenol A, and a propylene oxide adduct of bisphenol A. Among these, UV curable resins for coating optical fibers include polypropylene glycol (PPG) and polytetramethylene glycol (PTG).
Polyether urethane acrylates using as a polyether polyol component are widely used.

[0005]

The properties required for an ultraviolet curable resin for optical fiber coating are (1) low viscosity, normal temperature liquid and excellent workability, (2) sufficient curing even at low ultraviolet irradiation dose. However, it is excellent in productivity and (3) excellent in long-term reliability such as heat resistance, jelly resistance and hydrolysis resistance of the cured coating film.

When the above-mentioned general-purpose polyether is used as the polyether component of the polyether urethane acrylate, for example, when PPG is used, the viscosity is low and the workability is excellent, but the curability and heat resistance are long-term. It has both strengths and weaknesses, such as poor reliability. On the other hand, in Japanese Patent Application No. 4-18935, the present inventors
By using, for example, a random copolymer of butylene oxide and propylene oxide as a polyether component, we have proposed an ultraviolet-curable resin for optical fiber coating, which is excellent in these properties.

However, since the random copolymer contains a compound having no hydroxyl group, which is a by-product of the copolymerization reaction, when the urethane acrylate of this random copolymer is used in the ultraviolet curable resin composition. However, there is a problem that the reaction by-product that does not contribute to the ultraviolet curing reaction reduces the saturated gel fraction of the cured coating film.

The present invention has been made in view of the above circumstances, and an object thereof is to provide butylene excellent in long-term reliability such as curability, heat resistance, and jelly resistance, and having low viscosity and excellent workability. An object of the present invention is to provide an ultraviolet-curable resin composition for optical fiber coating, which exhibits the characteristics of a random copolymer of oxide and propylene oxide and further has an improved gel fraction.

[0009]

In order to solve the above-mentioned problems, the present invention uses (a) a polybutylene glycol as a trunk polymer and a polyether polyol obtained by block-copolymerizing an alkylene oxide, and (b) a polyisocyanate. And (c) a polymerizable unsaturated polyurethane (hereinafter referred to as a polymerizable unsaturated polyurethane of the present invention) obtained by reacting an isocyanate group-reactive active hydrogen and a compound having a polymerizable unsaturated group. An ultraviolet curable resin composition comprising: (1) a polymerizable unsaturated polyurethane of the present invention (2) a monomer having an ethylenically unsaturated bond and (3) a photopolymerization initiator.

The polymerizable unsaturated polyurethane used in the present invention is obtained by reacting a polyether polyol obtained by block copolymerizing alkylene oxide with polybutylene glycol as a trunk polymer, polyisocyanate and a hydroxy compound having an acryloyl group. Obtainable.

Examples of the alkylene oxide compound used in the block copolymer used in the present invention include ethylene oxide, propylene oxide, trimethylethylene oxide, tetramethylethylene oxide,
Butadiene monooxide, styrene oxide, α-
Methylstyrene oxide, 1,1-diphenylethylene oxide, epifluorohydrin, epichlorohydrin, epibromohydrin, glycidol, butyl glycidyl ether, hexyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, 2
-Chloroethyl glycidyl ether, cyclohexene oxide, dihydronaphthalene oxide, vinylcyclohexene monooxide, oxetane, tetrahydrofuran, tetrahydropyran and the like can be mentioned. Among these, the polyether polyol obtained by combination with propylene oxide is particularly suitable as a material constituting the polymerizable unsaturated polyurethane for coating an optical fiber.

Commercially available polyether polyols obtained by block copolymerizing propylene oxide with polybutylene glycol as a trunk polymer include, for example, "Z-30".
04 ”(manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

Examples of the polyisocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylylene diisocyanate, trimethylhexamethylene diisocyanate. , 1,5-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate,
Examples include lysine diisocyanate.

Examples of the hydroxy compound having an acryloyl group include hydroxyethyl acrylate and 2
-Hydroxypropyl acrylate, 2-hydroxybutyl acrylate, phenoxyhydroxypropyl acrylate, butoxyhydroxypropyl acrylate,
Pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, trimethylolpropane diacrylate, dipropylene glycol monoacrylate, 1,6-hexanediol monoacrylate, glycerin diacrylate, caprolactone modified 2-hydroxyethyl acrylate, stearic acid modified penta Examples thereof include erythritol diacrylate.

As the monomer having an ethylenically unsaturated bond used in the present invention, an acrylate compound is mainly used. When the cured film is required to have softness, a monofunctional (meth) acrylic acid ester compound is used. When the cured film is required to have hardness, a bifunctional or higher polyfunctional acrylic acid ester compound is used. Is commonly used.

Specific examples of the monomer having an ethylenically unsaturated bond used in the present invention include aromatic vinyl monomers such as styrene, chlorostyrene, divinylbenzene and the like; as a substituent, methyl, ethyl, propyl, butyl and amyl. , 2-ethylhexyl, octyl, nonyl,
Dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, phenoxyethyl, nonylphenoxyethyl, tetrahydrofurfuryl, allyl, methallyl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxy. Acrylate, methacrylate or fumarate having a group such as propyl, dimethylaminoethyl, diethylaminoethyl, nonylphenoxyethyl tetrahydrofurfuryl, etc .; ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol, Hexamethylene glycol, trimethylolpropane, glycerin, pentaerythritol and other mono ( Data) acrylate or poly (meth)
Acrylate; vinyl acetate, vinyl butyrate or vinyl benzoate, acrylonitrile, cetyl vinyl ether, limonene, cyclohexene, diallyl phthalate, 2-3.
-Or 4-vinylpyridine, acrylic acid, methacrylic acid, acrylamide, methacrylamide, N-hydroxymethyl acrylamide or N-hydroxyethyl acrylamide and their alkyl ether compounds, and 2 mol or more of ethylene oxide or propylene per 1 mol of neopentyl glycol. Di (meth) acrylate of diol obtained by adding oxide, di or tri (meth) acrylate of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane, and 1 mol of bisphenol A Di (meth) acrylate of diol obtained by adding 2 mol or more of ethylene oxide or propylene oxide, 2-hydroxyethyl (meth) acrylate 1
Examples thereof include reaction products of 1 mol of phenyl isocyanate or 1 mol of n-butyl isocyanate, poly (meth) acrylate of dipentaerythritol, and the like.

Further, N-vinyl-2-pyrrolidone, acryloylmorpholine, vinylimidazole, vinylcaprolactam, vinyl-p-tert-butylbenzoate, cyclohexyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate. At least one monomer selected from the group consisting of can also be used, and when used in combination with the above-mentioned (meth) acrylate having a functionality of two or more, the curability is improved, and a high gel fraction is obtained after curing, thereby providing a highly reliable material. be able to.

The photopolymerization initiator used in the present invention includes:
What is necessary is that a radical is generated by light and the radical efficiently reacts with the polymerizable unsaturated compound. There are a type in which a molecule is cleaved to generate a radical and a type in which a compound is used such as a combination of an aromatic ketone and a hydrogen donor.

Examples of the former include, for example, benzoyl ethyl ether, benzoin isobutyl ether,
Benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1
-Phenyl-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one and 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropanone-1 and the like.

Examples of the aromatic ketone of the latter example include benzophenone, 4-phenylbenzophenone, isophthalophenone, 4-benzoyl-4'-methyl-diphenylsulfide, 2,4-diethylthioxanthone and 2-isopropyl. Examples thereof include thioxanthone and 2-chlorothioxanthone, and examples of the hydrogen donor to be combined therewith include mercapto compounds and amine compounds, but amine compounds are generally preferable.

Examples of amine compounds include triethylamine, methyldiethanolamine, triethanolamine, diethylaminoethyl (meth) acrylate, p-dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N , N-dimethylbenzylamine and 4,
4'-bis (diethylamino) benzophenone and the like can be mentioned.

These photopolymerization initiators may be used alone or in combination of two or more kinds.

Further, as other additives, a thermal polymerization inhibitor, an antioxidant, a plasticizer, a silane coupling agent and the like can be added for the purpose of improving various characteristics.

The ultraviolet resin composition for coating an optical fiber of the present invention comprises (1) 10 to 80% by weight of a polymerizable unsaturated polyurethane, (2) 10 to 80% by weight of a monomer having an ethylenically unsaturated bond, and an optical resin. Polymerization initiator 0.1-10% by weight
It is preferable that it is blended from the range.

[0025]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, "part" and "%" represent "part by weight" and "% by weight", respectively.

First, a synthetic example of the polymerizable unsaturated polyurethane of the present invention will be shown.

(Synthesis Example 1) Polyether diol obtained by block copolymerizing propylene oxide (PO) with polybutylene glycol as a trunk polymer (number average molecular weight:
3,000, PO content: 10%) 2 mol and 3 mol of 2,4-tolylene diisocyanate were charged into a reaction vessel equipped with a nitrogen gas introduction tube, a stirrer and a cooling tube, and reacted at 70 ° C. for 2 hours. .

Next, 2-mol of 2-hydroxypropyl acrylate, a small amount of t-butylhydroquinone as a polymerization inhibitor and a small amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
1) was obtained. The resulting polymerizable unsaturated polyurethane (A-
The physical properties of 1) were as follows. Gardner dilution viscosity: VW (70% solid content in toluene) Residual isocyanate: 0.04%

(Synthesis Example 2) Random copolymer of butylene oxide and propylene oxide (number average molecular weight:
3,000, PO content: 10%) 2 mol, 2,4-
3 mol of tolylene diisocyanate was charged into a reaction vessel equipped with a nitrogen gas introduction tube, a stirrer and a cooling tube, and the mixture was heated at 70 ° C for 2
Reacted for hours.

Next, 2 mol of 2-hydroxypropyl acrylate, a small amount of t-butylhydroquinone as a polymerization inhibitor and a small amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
2) was obtained. The resulting polymerizable unsaturated polyurethane (A-
The physical properties of 2) were as follows. Gardner dilution viscosity: VW (70% solid content in toluene) Residual isocyanate: 0.04%

Examples and comparative examples of the ultraviolet-curable resin composition for coating an optical fiber of the present invention are shown below.

(Example 1) 50 parts of the polymerizable unsaturated polyurethane (A-1) obtained in Synthesis Example 1, 50 parts of nonylphenoxy polypropylene glycol monoacrylate and 2,
2 parts of 4,6-trimethylbenzoyldiphenylphosphine oxide were mixed and dissolved at 60 ° C. for 1 hour to give a viscosity of 65.
A liquid UV curable resin composition of 3 poise (25 ° C.) was obtained.

(Comparative Example 1) The procedure of Example 1 was repeated, except that the polymerizable unsaturated polyurethane (A-1) was replaced by the polymerizable unsaturated polyurethane (A-2). A liquid ultraviolet curable resin composition having a viscosity of 71.2 poise (25 ° C.) was obtained.

The following evaluations were carried out using the respective ultraviolet curable resin compositions obtained in Example 1 and Comparative Example 1, and the results are shown in Table 1.

(Evaluation of Curability-1) The ultraviolet-curable resin composition was placed on a glass plate to give a dry coating film thickness of 200 ± 20 μm.
Each of the above coatings was applied, and the amount of irradiation light was changed in a nitrogen atmosphere using a metal halide lamp of 80 W / cm to cure. The tensile modulus of the cured film was measured.

The tensile modulus of elasticity is measured according to JIS K7.
It carried out according to 113. Further, as an index of curability, the ratio of the tensile elastic moduli upon irradiation with 20 mJ / cm ² and 1 J / cm ² was taken, and the curing rate is shown in Table 1.

(Evaluation of Curability-2) The ultraviolet-curable resin composition was placed on a glass plate to give a dry coating film thickness of 200 ± 20 μm.
Each of the above coatings was applied, and then a cured film was formed by irradiating 1 J / cm ² in a nitrogen atmosphere using a metal halide lamp of 80 W / cm. Extraction was performed for 3 hours or more with a Soxhlet extractor using methyl ethyl ketone as a solvent, and the weight ratio before and after extraction was taken as the gel fraction.

(Evaluation of heat resistance) An ultraviolet-curable resin composition was applied on a glass plate so that the dry coating film thickness was 200 ± 20 μm, and then in a nitrogen atmosphere using a 80 W / cm metal halide lamp. It was cured with an irradiation light amount of 200 mJ / cm ² . This cured film was stored in air at 120 ° C. for 1 week, and then the tensile modulus was measured in the same manner as in the above method.
The ratio of this measured value to the initial value was used as an index of heat resistance.

(Evaluation of Jelly Resistance) An ultraviolet-curable resin composition was applied on a glass plate so that the dry coating film thickness was 200 ± 20 μm, and then in a nitrogen atmosphere using a 80 W / cm metal halide lamp. Irradiation light amount is 200 mJ / cm
Cured at ² . The cured film is adjusted to a state of 23 ° C. and 50% RH, and the weight M1 is measured. Then Jerry S
After immersing in YNCOLT (manufactured by SYNCO Chemical Co., Ltd.) at 85 ° C. for 7 days, it is taken out, the jelly on the surface is wiped off, and the weight M2 is measured. Weight change = M2 / M
1 × 100 (%) was used as an index of jelly resistance.

[0040]

[Table 1]

[0041]

The polymerizable unsaturated polyurethane of the present invention is
It improves the drawbacks of the polymerizable unsaturated polyurethane using a random copolymer of butylene oxide and propylene oxide, has excellent curability, and is also excellent in heat resistance and jelly resistance. Therefore, the ultraviolet-curable resin composition for optical fiber coating using the polymerizable unsaturated polyurethane of the present invention is excellent in workability and productivity, and coated with the ultraviolet-curable resin composition for optical fiber coating of the present invention. The optical fiber can obtain high reliability even in long-term use.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G02B 6/44 301 A 7036-2K G03F 7/027 513

Claims (3)

[Claims] 1. A polyether polyol obtained by block copolymerizing (a) polybutylene glycol as a trunk polymer with alkylene oxide, (b) polyisocyanate and (c) active hydrogen which reacts with an isocyanate group and a polymerizable monomer. A polymerizable unsaturated polyurethane obtained by reacting a compound having a saturated group. 2. An ultraviolet curable resin composition containing (1) the polymerizable unsaturated polyurethane according to claim 1, (2) a monomer having an ethylenically unsaturated bond, and (3) a photopolymerization initiator. 3. An ultraviolet-curable resin composition for coating an optical fiber, which comprises the ultraviolet-curable resin composition according to claim 2.